Question

i just created a win form app with a Gecko.GeckoWebBrowser on it when i navigate to a page with a anchor that has the href attribute set to javascript:print() and click on it, the print dialog is displayed, but it turns out that when i hit cancel button on that dialog the Gecko.GeckoWebBrowser is destroyed , i mean the control receives a WM_DETROY message any clue of what is could be happen here? how i can prevent it? i modified the gecko fx Gecko.GeckoWebBrowser windows procedure and catch and bypass that windows message but it seems that is not helping btw i am using xulrunner-11.0.en-US.win32 and geckofx-11.dll regards

Answer 1

从看火法则,它像火法一样发出WM_DESTROY信息。

nsPrintingPromptService::ShowPrintDialog(nsIDOMWindow *parent, nsIWebBrowserPrint *webBrowserPrint, nsIPrintSettings *printSettings)
{
    NS_ENSURE_ARG(parent);

    HWND hWnd = GetHWNDForDOMWindow(parent);
    NS_ASSERTION(hWnd, "Couldn t get native window for PRint Dialog!");

    return NativeShowPrintDialog(hWnd, webBrowserPrint, printSettings);
}



nsresult NativeShowPrintDialog(HWND                aHWnd,
                               nsIWebBrowserPrint* aWebBrowserPrint,
                               nsIPrintSettings*   aPrintSettings)
{
  PrepareForPrintDialog(aWebBrowserPrint, aPrintSettings);

  nsresult rv = ShowNativePrintDialog(aHWnd, aPrintSettings);
  if (aHWnd) {
    ::DestroyWindow(aHWnd);
  }

  return rv;
}

我不肯定为什么会这样做。

界定这一点的一些备选办法:

turn on "print.always_print_silent"
provide and register your own nsIPrintingPromptService
provide and register your own nsIWindowWatcher service.

The nsIWindowWatcher way look as the appropriate way to do this view at GetHWNDForDOMWindow:

HWND
nsPrintingPromptService::GetHWNDForDOMWindow(nsIDOMWindow *aWindow)
{
    nsCOMPtr<nsIWebBrowserChrome> chrome;
    HWND hWnd = NULL;

    // We might be embedded so check this path first
    if (mWatcher) {
        nsCOMPtr<nsIDOMWindow> fosterParent;
        if (!aWindow) 
        {   // it will be a dependent window. try to find a foster parent.
            mWatcher->GetActiveWindow(getter_AddRefs(fosterParent));
            aWindow = fosterParent;
        }
        mWatcher->GetChromeForWindow(aWindow, getter_AddRefs(chrome));
    }

    if (chrome) {
        nsCOMPtr<nsIEmbeddingSiteWindow> site(do_QueryInterface(chrome));
        if (site) 
        {
            HWND w;
            site->GetSiteWindow(reinterpret_cast<void **>(&w));
            return w;
        }
    }

友情链接